The national concern about breast cancer has mandated a focus on translational research to introduce new laboratory innovations rapidly into the clinic. The overall goal is to improve the treatment of breast cancer and to develop new strategies in breast cancer prevention. To achieve this goal requires an understanding of both basic laboratory strategies and clinical issues relevant to breast cancer. Northwestern University Medical School has responded to the national concern by establishing a new breast center. The aim of the current proposal is to develop a breast cancer program with specific research laboratories and a centralized team of basic scientists and clinicians through the Robert H. Lurie Cancer Center. The research team will have established links with the multidisciplinary breast cancer treatment team. The Robert H. Lurie Cancer Center is an NCI- designated cancer center integrating the expertise and resources of the Medical School departments with its five affiliated hospitals along with those of basic science departments located on the Evanston campus. The institution has significant strengths in breast cancer-related basic and clinical research. The goal is to establish a new program from the existing team of talented investigators. Four pilot projects will be supported for year 1 of this proposal. Project #1 involves studying gene therapy for treatment of breast cancer using in vivo administration of therapeutic vectors using breast cell-specific promoters. Project #2 involves production of mutant estrogen receptors to block normal receptor mediated signalling pathways. Project #3 assesses the endocrine status of breast cancer patients receiving tamoxifen. Project #4 is to develop assays to measure growth factors in breast fluid to identify potential intermediate biological markers for breast cancer. The newly recruited directors of the Program are V. Craig Jordan, Ph.D., D.Sc., a scientist, and a breast cancer surgeon, Monica Morrow, M.D.. The team is internationally known for their pioneering work in breast cancer and will provide a unique opportunity to develop a first class breast cancer program at the Lurie Cancer Center.